DALLAS (CBS 11 NEWS) – J.D. Womack woke up to ice in his pool and pond, and a broken heater in his greenhouse. “I thought it was my thermometer and heater quit working.”

The low temperatures in North Texas created a high demand for electricity. “It’s cold, very cold, very serious,” said Womack who’s lived in his Garland home for 16 years.

There was such a high demand for power this morning, that ERCOT, which runs most of the state’s power grid, warned residents and businesses across the state around 7 AM there was a risk of rolling power outages — unless people cut back on their use of electricity.

ERCOT’s director of system operations Dan Woodfin says two large power plants in North Central Texas went offline due to the frost weather. “Based on the preliminary information, it appears both of them related to freezing of the instrumentation that’s used to provide controls for the plant.”

Woodfin says ERCOT imported power from the east coast and from Mexico.

Had one other power plant gone offline this morning, ERCOT says it would have started the rolling blackouts.

That happened during Super Bowl week here in February, 2011 when a quarter of the state’s power plants went offline during an ice storm.

Ercot is still asking people to conserve power saying demand will be high tomorrow morning.

Not everyone believes it.

Cole Hatcher of Dallas said, “This advice is being given by people who are in warm offices. For the rest of us, if we’re cold, we’re going to turn up the heat.”

But Womack disagrees. “Everyone has to do their part.”

Ercot has several suggestions on how you can conserve power: Keep your thermostat at 68 degrees, unplug unnecessary appliances and lights, and don’t use washers, dryers, or electric ovens in key times from 6-9 AM and 4-8 PM.

Ercot has also asked all power plant operators to delay any maintenance and keep their plants online, and to make sure the facilities are prepared for the cold.